5. Neckera Hedw.   平藓属   ping xian shu

Sp. Musc. Frond. 200. 1801.

Neckeradelphus Laz., Bot. Žurn. (Kiev) 2(1): 86. 1941.

 

Plants usually medium-sized, sometimes small or rather large, yellowish green when young, brownish green when old, often glossy, in loose or flattened mats. Primary stems creeping, mostly with brownish rhizoids; secondary stems ascending or pendulous, complanately foliate, simple below, unipinnately or rarely 2–3-pinnately branched above; oval or rounded in cross section, a central strand absent; branches obtuse or slenderly attenuate at the apex, sometimes with flagelliform branches. Leaves arranged in 8 rows, often complanately and obliquely appressed on stems, broadly ovate, lingulate, oblong-lingulate, or ovate-lingulate, sometimes undulate or irregularly undulate, acuminate, acute, narrowly obtuse, or rounded-obtuse at the apex; margins serrulate to serrate above, entire below, often incurved on one side at the base; costae single, reaching above mid-leaf or longer, rarely double, weak, or absent; leaf cells smooth, apical and upper cells oval, rounded-quadrate, or rhombic to shortly rhomboidal; median cells elongate; basal cells more elongate to linear, thick-walled, porose; alar cells sometimes differentiated, quadrate to shortly rectangular. Autoicous or dioicous. Perichaetia mostly on secondary stems; inner perichaetial leaves sheathing at the base. Setae short to elongate; capsules immersed to long exserted, ovoid to cylindrical; opercula conic at the base, often obliquely rostrate; annuli sometimes well developed; peristome double; exostome teeth lanceolate, light yellow, smooth or finely papillose, sometimes striolate at the base; endostome segments usually filiform or linear, sometimes reduced; basal membrane low; cilia often absent. Calyptrae cucullate, sometimes hairy. Spores spherical, finely papillose.

 

1. Plants not complanately foliate; leaves lingulate, narrowed from an ovate base, rounded, coarsely dentate at the apex; costae single, up to 2/3 the leaf length, sometimes curved near the tips............ 15. N. undulatifolia

1. Plants complanately foliate; leaves oblong-ovate or broadly lingulate from an ovate base, serrulate at the apex; costae double, short and weak, or single, disappeared above mid-leaf, straight at the tips...................... 2

2. Stems 2–3-pinnately branched; leaves not densely appressed.............................................. 9. N. neckeroides

2. Stems usually unipinnately branched or irregularly pinnately branched, rarely 2–3-pinnately branched; leaves closely and densely appressed, sometimes loosely appressed............................................................. 3

3. Capsules immersed; setae less than 0.5 cm long.................................................................................................. 4

3. Capsules long-exserted; setae 2–3 cm long........................................................................................................ 10

4. Costae double, usually short and weak............................................................................................................... 5

4. Costae single, stout.............................................................................................................................................. 7

5. Leaves broadly ovate, strongly undulate above, serrate at the apex.............................................. 10. N. pennata

5. Leaves oblong-ovate or narrowly to somewhat broadly ovate, not undulate above, serrulate at the apex........ 6

6. Leaves equally wide below mid-leaf; costae usually ca. 1/3 the leaf length; exostome teeth striolate at the base................................................................................ 1. N. borealis

6. Leaves wider below mid-leaf; costae usually ca. 1/5 the leaf length; exostome teeth smooth............... 8. N. laevidens

7. Leaves usually decurrent at the base.............................................................................................. 3. N. decurrens

7. Leaves not decurrent at the base............................................................................................................................. 8

8. Leaves ovate, strongly concave, irregularly undulate.................................................................... 6. N. humilis

8. Leaves oblong-ovate to ovate-lingulate, not distinctly concave, slightly undulate or not undulate.............. 9

9. Inner perichaetial leaves narrowly lanceolate; leaves ovate-lingulate; costae reaching beyond mid-leaf; leaf cells elongate-rhomboidal, usually unevenly thick-walled, porose.............................................. 16. N. yezoana

9. Inner perichaetial leaves shortly lanceolate; leaves ovate or oblong-ovate; costae ending at mid-leaf; leaf cells rhomboidal, evenly thick-walled.......................................................................................... 5. N. goughiana

10. Branches short, 0.5–1.0 cm long; costae double, short........................................................ 4. N. flexiramea

10. Branches usually more than 1.0 cm long; costae single............................................................................... 11

11. Pseudoparaphyllia many; basal leaf margins on both sides incurved or recurved............ 14. N. setschwanica

11. Pseudoparaphyllia few; basal leaf margins incurved on one side, rarely on both sides................................. 12

 12. Leaves oblong-ovate, acuminate at the apex, distinctly asymmetric.......................................... 7. N. konoi

 12. Leaves ovate-lingulate, broadly acute, obtuse, or shortly apiculate at the apex, somewhat asymmetric 13

13. Plants usually less than 5 cm long; leaf apices acute............................................................. 11. N. perpinnata

13. Plants usually more than 5 cm long; leaf apices obtuse or shortly apiculate................................................. 14

 14. Stems 2–3-pinnately branched; basal leaf margins incurved on both sides......................... 2. N. crenulata

 14. Stems unipinnately branched; basal leaf margins incurved on one side.................................................... 15

15. Plants usually more than 10 cm long, flagelliform branches often present; leaf length and width ratio more than

15. Plants usually 5–10 cm long, flagelliform branches absent; leaf length and width ratio less than ca. 2.5: 1;

 16. Leaf cells not sinuously thick-walled, weakly porose; inner perichaetial leaves narrowly ovate or triangular at

       the base............................................................................................................................. 13. N. serrulatifolia

 16. Leaf cells sinuously thick-walled, porose; inner perichaetial leaves broadly ovate at the base........... 17. N. yunnanensis